Internal, or non-vital, bleaching is used to lighten a darkly discolored
tooth that has had root canal therapy. A chemical
oxidizing agent is placed within the coronal portion of a tooth to remove
tooth discoloration. It may be performed in the dental office using a
procedure known as "chair side bleach." In this procedure, bleach
crystals are placed inside the tooth, left for a period of time, and then
removed before leaving the office. This may be done once or several times,
depending upon the discoloration of the tooth. Another method is known
as "walking bleach". In this procedure, bleach crystals are
placed inside the tooth, left for several days and then the patient returns
to the dental office to have the bleach crystals removed. Again, this
procedure may be performed one or more times, depending upon the discoloration
of the tooth.